A chemistry teacher needs to react barium chlorate salt with an acid for a demonstration. To make the reaction go faster, she crushes the salt until it is a fine powder. This makes the reaction faster by: A. increasing the surface area of the salt. B. increasing the concentration of the salt. C. increasing the temperature of the salt. D. increasing the pressure of the salt.

Option A, increasing the surface area of the salt

Explanation:

For a reaction to occur, there must be collision between reactant molecules. One of the factor that increases the collision between reactant molecules is surface area of the solid reactant. Therefore, increase in surface area, increases the rate of reaction.

For example, consider reaction between calcium carbonate and hydrochloric acid

Calcium carbonate is solid and powered calcium carbonate reacts faster because of increase in surface area.

Therefore, among the given option, A is the correct answer.